Subtract 56/81 from 42/45
42/45 - 56/81 is 98/405.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 81 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 45 × 9 = 405,
42/45 = 42 × 9/45 × 9 = 378/405 - Likewise, for the 2nd fraction, since 81 × 5 = 405,
56/81 = 56 × 5/81 × 5 = 280/405 - Subtract the two like fractions:
378/405 - 280/405 = 378 - 280/405 = 98/405
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/45-56/81 42/90-56/81